Cerebrovascular Anatomy M. Christopher Wallace M.D. The Toronto Western Hospital, University Health...

Cerebrovascular Anatomy

M. Christopher Wallace M.D.

The Toronto Western Hospital,

University Health Network

University of Toronto

Postgraduate Lecture Series

Division of Neurosurgery

Friday October 6, 2000

Collateral Circulation

• Circle of Willis• Variation• Leptomeningeal

Collateral

Cerebral Autoregulation

• Maintenance of blood flow during variation in blood pressure

• Change in blood flow related to metabolic activity

Mechanism for Cerebral Autoregulation?

• Myogenic

• Neurogenic

• Metabolic

Measurement of Cerebral Blood Flow

• Seymour Kety• Delivery of blood flow to given wt of brain per

time period– 50ml/100grams/minute

Brain takes 12-15% of cardiac output

Internal Carotid Artery

• Divisions: cervical, petrous, cavernous, infraclinoid, supraclinoid

• Branches: meningohypophyseal trunk• dorsal meningeal artery, tentorial artery, inferior

hypophyseal

• artery of the inferior cavernous sinus

• capsular arteries of McConnell

Internal Carotid Artery

Internal Carotid Artery

• Supraclinoid

• Branches – Ophthalmic– Posterior communicating– Anterior choroidal

Bifurcation

Middle Cerebral Artery

• Variation

• Divisions (M1-M4)

• Lenticulostriate arteries

– medial

– lateral• putamen, caudate, sup

internal capsule

Anterior Cerebral Artery

• Variation• Divisions (A1-A4) • Anterior communicating artery

• Lamina terminalis, septal region, fornix, preoptic/hypothalamus

Recurrent artery of Heubner

Anterior putamen, pallidum and internal capsule